@book{9993,
	author = {Polit, Denise F. and Beck, Cheryl Tatano.},
	title = {Nursing research :},
	publisher = {Lippincott Williams & Wilkins,},
	year = {c2004.},
	address = {Philadelphia :},
	edition = {7th ed.},
	url = {http://www.loc.gov/catdir/enhancements/fy0711/2002043422-d.html}
}